I just recently changed the automatic transmition on my 88 4x4 toyota four runner. Everything appears to be working well except for the fact that it will not hit forth gear, overdrive. First, second and third gear all smooth no problem just wont drop into overdrive. The Overdrive light in the cab blinks off and on, which it never used to do, and will not hit forth gear. Is there something that the blinking overdrive light is trying to tell me or warn about, please advise. Also will running the trans with only the first three gears burn out the clutches or other mechanisms in the tranny?

 

I am not familiar with the older A/T's, is there a button to switch the O/D on and off? If there is, me thinks wiring problem.

 

That means there is a trouble code set by the ECU.

Try this link for getting the code:
http://personal.utulsa.edu/~nathan-b...85diagnosi.pdf

 

I had a flashing over drive light after not driving my truck for a couple of weeks. Not sure what it means but it has not returned after the first start up

 

Blinking is a form of getting your attention. Agree with mt goat. I'm not good with A/T, but had to fix my wifes subaru, (i hate subarus). Blinking light was a sure sign, of help me.

 

Yeah...pull the codes...but if your prob is just no o.d....then I would suspect the no 2 solenoid. Pull the codes and report back, if it is a solenoid...it's an easy fix, they are very easy to get to....not sure about how much they cost...but easy to get to.